Cindy Patriarchias (L), 33, and Edmond Gonzales (R), 37, were arrested after their 8-year-old adoptive daughter was found locked in a cage while they went out to see a movie, police said January 29, 2013. (AFP PHOTO/Las Cruces Police Department)

SANTA FE, New Mexico - Police in New Mexico found an 8-year-old girl locked in a cage in a darkened mobile home, authorities said on Tuesday, adding that they charged the girl's adoptive mother, who had gone to the movies, with child abuse.

Cindy Patriarchias, 33, and her boyfriend were arrested after police found the caged girl on Friday evening, Las Cruces Police Department spokesman Dan Trujillo said.

He said police, acting on a tip from the woman's estranged husband, found the girl in the corner of a bedroom locked inside the cage, about four feet high, slightly more than two feet wide and about five feet long.

The homemade wooden structure had two latches and a baby crib mattress on the floor, Trujillio said.

He said Patriarchias had been charged with one count of negligent child abuse while her boyfriend was charged with one count of negligently permitting child abuse. Patriarchias was released on bond on Tuesday but her boyfriend is still being held, authorities said.

The girl was seen by medical personnel but showed no visible signs of physical abuse. She apparently suffers from microcephaly, a condition in which the head or cranial capacity is abnormally small, Trujillo said.

He said detectives did not know why the girl was left locked in the cage. She and three of Patriarchias' other children had been placed in state custody, he said.